Gas burner for water wall furnace



March 6, 1956 R. D. REED GAS BURNER FOR WATER WALL FURNACE Filed March 5, 1951 IN VENTOR F05A='7" 0. FEED,

ATTORNEY United States Patent GAS BURNER FOR WATER WALL FURNACE Robert D. Reed, Tulsa, Okla, assignor, by mesne assign= ments, to John Zink Company, Tulsa, Okla., 21 corporation of Delaware Application March 5, 1951, Serial No. 213,901

1 Claim. (Cl. 158116) The present invention relates to burners for use in association with the tubes which carry water along the inner wall of a furnace so that more than one type of fuel may be burned in the furnace and to provide for heating in the event that one source of fuel should become exhausted.

The prior art includes burner structures adapted to be mounted on the wall of a furnace so as to fire from between the water tubes which are arranged along the inner face of the fire box wall of a boiler or furnace. Such prior devices are usually of circular construction which requires that the water tubes be bent or arcuate shaped to permit installation of the burner. Such alteration of the water tube is a costly operation and one of the objects of the present invention is to provide a burner structure that may be mounted in position to fire between the tubes of a water wall furnace without the necessity of rearranging the straight pipes which form the steam generating tubes.

Another object of the present invention is to provide a burner structure so constructed as to partly span an outer circumferential portion of a tube of a water wall furnace so as to properly position the burner head to discharge the fuel mixture across streams of secondary air entering between the water tubes and to so position the burner head as to be shielded by the water tube.

Another object of the invention is to provide a fuel burning device so constructed that the burner head may straddle a water tube of the water wall furnace to discharge the fuel mixture in separate streams to provide a heating flame on each side of the water tube which is straddled and to direct the main flames of the burner at an angle to the secondary air moving into the furnace and induced to flow inwardly by the draft present in the fire box along each side of the water tube which is straddled.

Other objects and features of the invention will be more apparent as the present disclosure proceeds and upon consideration of the following detailed description and the accompanying drawing wherein an exemplary embodiment of the invention is disclosed.

In the drawing:

Fig. 1 is a side elevational view of a burner head embodying the invention.

Fig. 2 in the left hand portion is a plan view of the burner head while the right hand portion is a section taken on the line 22 of Fig. 1.

Fig. 3 is a plan view partly in section showing a burner exhibiting the invention in association with a water tube with a fragmentary portion of a furnace wall illustrated in section.

Fig. 4 is a diagrammatic plan view showing one arrangement of burners with the tubes of a water wall furnace.

Fig. 5 is a similar view showing another arrangement of the burners in association with the tubes of a water wall furnace.

The usual water wall furnace includes a plurality of tubes 11 arranged along the inner face 12 of a furnace wall such as shown at 10. These tubes 11 are filled with tubes are of different size.

. is in part formed by the wall 13.

water and form a part of the steam generating equipment in combination with the usual boiler tubes. The water tubes 11 in addition to serving as means for rapid absorption of heat from the fire box also serve to protect the furnace wall 10 from heat damage. The furnace is usually heated by a primary heat source, such as coal burned in the fire box. The water tubes as represented at 11 usually have an outside diameter of about three inches and these tubes are spaced from each other on approximately six or seven inch centers. An elongated opening may be provided in the furnace wall in which one or more burner heads of the type hereinafter described may be mounted.

The burner is shown more clearly in Figs. 1 and 2 and the device is of elongated construction. The burner head 15 is provided with an intermediate wall surface 16 which is impervious and may be substantially flat as shown in Fig. 2. This wall surface 16 is provided on the burner head for abutting one of the water tubes 11 as illustrated in Fig. 3. The wall surface 16 thereby positions the head 15 in relation to the water tube. A wall 13 extends angularly from the surface. 16 at approximately one hundred and thirty-five degrees, although this angle may be varied particularly when the diameters of the water A similar angular wall 19 is provided on the burner head 15 which may also be at an angle of approximately one hundred and thirty-five degrees with reference to the fiat wall surface 16. An elongated slot 21 is provided in an ear portion 22 which A similar shaped slot 23 is provided in the car 24 which is in part formed by the wall 1?. The burner head is provided with converging rear walls 26 and 27 in proceeding rearwardly from the front end of the burner the rear portion of the burner terminates in a central opening 2%; which carries internal threads for connection to a fuel supply pipe 29 as shown in Fig. 3.

A mixture of gas and primary air is supplied into the pipe 29 through a mixing device as represented at 31. The gas under pressure is supplied into the gas connection 32 and through a mixing orifice 33. Air is entrained and moves into the mixing device 31 in the direction of the arrows 34. The primary air is thereby mixed with the fuel and moves forwardly in the pipe 29 and into the hollow burner head 15. A main flame is created by combustion of the fuel mixture issuing from each of the elongated discharge slots 21 and 23 to provide two main flames throughout the length of the burner head with each having a pattern somewhat as indicated in phantom lines at 36 in Fig. 2. The main flames are thus projected on each side of the water tube as will be apparent from a consideration of Fig. 3.

The car 22 of the burner head is provided with an arcuate wall portion 37 as shown in Fig. 2. Two rows of discharge ports 38 and 39 are provided which extend through the arcuate wall 37. The axes of the discharge ports and 39 are so angularly related to each other that the fuel mixture issuing from these ports converge at a point indicated at X. The fuel mixture may escape from the row of discharge ports 38 and the rows of discharge ports 39 which are both spaced along the length of the burner head and the fuel mixture issuing from these ports is in addition to that escaping from the elongated slot 21. A similar arrangement of ports is provided in an arcuate wall 41 forming a part of the car 24 of the burner head 15. Two rows of spaced discharge ports (not shown) are provided in the arcuate wall 41 so that the fuel mixture issuing from these spaced discharge orifices converge in the manner as described in connection with the ports 38 and 39. l

A burner head 15 may be mounted in the opening in the furnace wall or a plurality of burner heads may be emmerely lengthening the opening in the furnace wall along one of the water tubes 11. Gas is supplied under pressure into the pipe connection 32 and the gas and air is mixed .in proper proportions .in the mixing device 31. The fuel mixture moves through the pipe 29 and escapes through the elongated discharge slots 21 and 23 to provide a main fiame at each side of the water tube 11. The normal furnace draft provided in the fire box of the furnace creates secondary air currents which move in the direction of the arrows 43 in Pig. 3. The volume of secondary air may be controlled by adjusting the position of the door 44 which slides on the pipe 29.

The fuel mixture issuing from the rows of orifices 38 and 39 provide for impingement of the streams of fuel being discharged through these ports. The major portion of the fuel is discharged through the elongated slot 21 and smaller portions of the fuel mixture flows through the angularly disposed ports 38 and 39. The inductive effect of the fuel flowing through the elongated slots draw the fuel after emergence from the ports 38 and 39 into the fuel stream issuing from the elongated slot 21. Thus gases co-rningling in the zone X throughout the length of the burner head are drawn into the main flame 36. A constant rekindling of the fuel in the presence of the slot 21 is thereby provided even though there is an unusual rapid radiation of heat from the flame to the water tubes. A similar operating condition exists at the opposite side of the burner head in association with the slot 23. The fuel issuing from the elongated slot 23 draws fuel after emergence from the angular ports of the arcuate wall 41 into the main stream issuing from the elongated slot 23. Thus constant rekindling of the fuel issuing from the elongated slot 23 is maintained at this side of the burner head.

A burner head of the type herein disclosed may be mounted behind adjacent water tubes 11 as shown in Fig. 4 and any number of burner heads 15 may be mounted in end-to-end relationship along any one of thewater tubes 11. It is also possible to arrange the burner heads 15 in association with alternate water tubes 11 as shown in Fig. 5. It will be observed that burner head is in each type of mounting concealed in back of the associated water tube. Thus slagging condition existing in the fire box will not affect operation of the burner.

While the invention has been described with reference to specific structural features and with regard to one type of burner it will be understood that changes may be made in the burner structure as well as the mounting thereof in association with a water wall furnace. Such modifications and others may be made without departing from the spirit and scope of the invention as set forth in the appended claim.

What I claim and desire to secure by Letters Patent is:

An elongated fuel burner head for gaseous fuel comprising, an intermediate front wall extending throughout the length of the burner head, a Wall extending forwardly from one edge of said intermediate wall at an obtuse angle with respect thereto and extending throughout the length of the burner head, a second angular wall extending forwardly from the other edge of the intermediate wall at an obtuse angle with respect thereto and extending throughout the length of the burner head, walls converging towards each other in proceeding rearwardly from ends of said burner head and having a central opening therein, wall means cooperating with one angular wall providing a hollow ear throughout the length of the burner head, additional wall means cooperating with the other angular wall providing a hollow ear extending throughout the length of the burner head, each ear having a slot therein extending throughout the length of the burner head with an edge of the slot defined by an inner surface of the associated angular wall, means for supplying a gaseous fuel mixture into the burner head through said opening, means guiding secondary air for movement over the outer surfaces of said wall means, a concave surface in an outer portion of each wall means generated about an axis substantially parallel to the length of the burner head, and said wall means having spaced discharge ports therethrough converging at'the concave surface through which minor portions of the fuel mixture may escape in directions generally transverse to the direction of movement of the secondary air for rekindling the fuel mixture discharged through said slots.

References Cited in the file of this patent UNITED STATES PATENTS 1,105,031 Hagemeyer July 28, 1914 2,119,580 Hardgrove June 7, 1938 2,119,581 Sullivan June 7, 1938 2,462,704 Zink Feb. 22, 1949 2,525,960 Shaw Oct. 17. 1950 

